A method is disclosed for isolating both free and protein-associated DNA from bodily fluids, such as urine, saliva, serum, tears, sweat, cerebral spinal fluid, and plasma. The method comprises as a first step concentrating and isolating both the free DNA and the proteins present in the bodily fluid. The proteins are then digested in order to release the formerly protein-associated DNA from the isolated proteins. Lastly, the free and formerly protein-associated DNA can be isolated and purified.